As more functions and devices are being controlled by computer systems and over computer networks, there is a potential for unauthorized users/applications to attempt to control these functions and devices. For example, as homes or automobiles become more computerized it may be possible for unauthorized computer applications to access and change certain operational parameters associated with various devices that are computer controlled. While actions of the unauthorized computer application may be completely unintentional, the results can be serious.
One example can be found in controlling the volume of an audio system within a vehicle. Here, the computer applications are arranged to set and maintain the volume level of the audio system or a select portion thereof. If an unauthorized computer application unintentionally, or worse intentionally, attempts to change the volume level the occupants and more particularly the driver may become irritated. For example, certain high quality “auto PCs” output well over 100 Watts of sound. If the volume level were to unexpectedly change from a low or moderate level to a high or maximum level, the occupants will not be amused.
Other examples include controlling devices or appliances in a home or business. Here, various computer applications can communicate controlling information to the devices/appliances. Consequently, an unintended situation might arise if an unauthorized computer application attempts to control the device/appliance.
Thus, there is a need for methods and arrangements for controlling access to computer controlled functions and devices. Preferably, the methods and arrangements will significantly reduce the possibility of unauthorized computer applications from unintentionally or intentionally changing the operation of the functions/devices, without overly burdening the user or the underlying computer systems and networks. Furthermore, it would be desirable for the methods and arrangements to be secure and modular in design to allow for wide dissemination without compromising certain security features.